Hydrotropism

Q.

What is chemotropism? Give one example.

Q.

Write the differences between growth dependent movements and growth independent movements in plants.

Q.

What are the factors that affect the growth of the tree?

Q.

How does chemical coordination occur in plants?

Q.

Non-directional movement of plants in response to external stimuli is called:

1. Ripening

2. Nastic Movement

3. Growth

4. Tropism

Q.

What is the function of chemical messengers?

Q.

What is tropism?

Q.

With the help of an experiment, prove that roots are more positively hydrotropic than geotropic.

Q.

Give one example each of a plant part:

(a) Which is positively hydrotropic as well as positively geotropic.

(b) Which is positively phototrophic but negatively geotropic.

Q.

Plants do not have a nervous system they do not show any kind of coordination do you agree with the statement why or why not

Q.

Name any two types of tropism?

Q.

Which of the following terms denotes the movement of the root of a plant towards moisture in the soil?

(a) thigmotropism

(b) chemotropism

(c) hydrotropism

(d) geotropism

Q.

Question 20
The substance that triggers the fall of mature leaves and fruits from plants is

(a) auxin
(b) gibberellin
(c) abscisic acid
(d) cytokinin

Q.

(a) What does a plant root do in response to water? What is this phenomenon known as?

(b) What happens to the moonflower (i) during the daytime, and (ii) at night? What is this phenomenon known as?

Q.

Which of the following acts as a stimulus in the process of hydrotropism?

(a) hydrocarbon

(b) hydrogen oxide

(c) hydrogen chloride

(d) hydrogen peroxide

Q.

Roots are said to be ________as they grow towards gravity.

Q. Explain nastic movements. [3 MARKS]

Q.

Name the receptor associated with:

Smell

Q.

Briefly explain chemical coordination in plants.

Q.

What kind of plant movement is shown in the given diagram and explain it briefly?

Q.

The movement of plant due to touch is called

1. Phototropism

2. Thigmotropism

3. Geotropism
4. Chemotropism

Q.

Give one example of plant part. [2 MARKS]
A. Which is positively hydrotropic as well as geotropic.
B. Which is positively phototropic but negatively geotropic.

Q. Phototropic movements of roots and stems are due to:

1. Action of gravity
2. Effect of light
3. Differential hormonal effect
4. Epinasty and hyponasty

Q. What is hydrotropism? Describe an activity to demonstrate hydrotropism.

Q.

How does chemical coordination place in plants?

Q. What are tropic movements or tropism in plants?

Q. Growth of plant towards stimulus is called as

1. Positive tropism
2. Upward tropism
3. Negative tropism
4. Downward tropism

Q.

How does chemical coordination occur in plants?

Q. Describe an experiment that can be used to demonstrate hydrotropism.
[5 Marks]

Q. Following are the misconceptions about root hydrotropism. State whether they are correct or not.
i. The greater growth of roots in moist soil zones than in dry soil zones is not usually a result of hydrotropism. Hydrotropism requires a root to bend from a drier to a wetter soil zone. Roots require water to grow so roots that happen to be in moist soil will grow and branch much more than those in dry soil.
ii. Roots cannot sense water inside intact pipes via hydrotropism and break the pipes to obtain the water.
iii. Roots cannot sense water several feet away via hydrotropism and grow toward it. At best hydrotropism probably operates over distances of a couple millimeters.

1. (i) and (iii) are correct.
2. None of the above are correct.
3. (i) and (ii) are correct.
4. All are correct.